Clamp



y 1950 c. M. WOODWARD EIAL 2,514,273

CLAMP Filed April 15, 1947 Fla. 2.

FIG. 4.

FIG. 3.

INVENTORS CHARLES MAYNARD WOODWARD HAR/g); BERTHOLD BOLLER A 7' TORNE VS Patented July 4, 1956 CLAMP Charles Maynard Woodward, Pasadena,

and

Harry Berthold Boller, Alhambra, Calif.; said Boller assignor to said Woodward Application April 15, 1947, Serial No. 741,612

10 Claims.

This invention is concerned with pinch clamps. It provides improved apparatus of general utility but is particularly adapted for the control of intravenous anesthetics.

In one type of intravenous anesthesia, a liquid anesthetic and a saline solution are employed, the flow of one being interrupted during the administration of the other. The flow of the saline solution may continue for relatively long periods, in which case it is desirable to lock the clamp which controls this flow in open position. The flow of the anesthetic, on the other hand, must be subject to much more careful control, and its clamp should remain open only as long as the anesthetist exerts force upon it. Customarily the liquids flow by gravity from head tanks or the like through a pair of flexible rubber tubes united with a Y disposed immediately ahead of the hypodermic needle. The use of separate clamps on the two tubes is inconvenient.

We have developed a multiple clamp which is particularly adapted to the control of the anesthetic processes described above. It is provided with a single control which can be operated with one hand and which (a) assures that one clamp is closed when the other is open; (1)) at another position of the control permits both to remain closed; and (c) is provided with a locking device so that the clamp regulating the saline flow can be locked open.

In its preferred form, the apparatus of the invention is so constructed that its two clamps may each be opened at their sides to permit insertion of the fiexible tubes. This is advantageous, since it is often inconvenient or impossible to slide the clamps into position over free ends of the tubes. The apparatus is simple and inexpensive to construct and assemble, positive in operation, convenient to employ and affords great safety-a highly desirable feature in apparatus employed for intravenous injection.

In essence, the multiple clamp of the invention comprises a body having clamping surfaces side by side with two bores extending inwardly in the body from each face, two clamps disposed respectively adjacent the clamping faces, two rods attached respectively to the clamps with their free ends slidably mounted in the bores, a cam rotatably mounted in the body in contact with the free ends of the rod members and arranged to press either of the rods and their accompanying clamps outward without substantially moving the other rod.

Preferably each clamp is provided with a springing means which presses it toward the respective clamping face on the body. Conveniently these springs are helical and are mounted respectively in the two bores around the rods.

In the preferred clamp structure of our invention, each of the clamps is provided with a short rod. parallel to the long rod and designed to slide in another bore extending inward from the clamp face. The spring which presses the clamp toward the face and the short rod are so proportioned that the short rod may be pulled completely out of its bore so that a flexible tube may be admitted to the space between the clamp and the clamping face. In such a structure, it is desirable that the long red be rotatable in its bore so that the clamp may be swung to one side of its clamping face.

The cam employed to control the action of the two long rods preferably is mounted with its axis of rotation perpendicular to a plane passing through the two rods. We prefer to employ a circular cam with a slit cut in its periphery and transverse to its axis. The ends of the two rods project into this slit and their movement is controlled thereby.

As indicated above, the flow controlled by one A of the clamps may continue for a substantial period so that it is desirable to be able to lock this clamp open. A convenient method is to provide a catch on the free end of the rod which controls this clamp. This catch tends t jam the cam when the clamp is open. However, upon rotating the cam by means of a lever or the like, the catch is released.

The clamp body conveniently is cut from a metal sheet and is provided with a pair of ears on its end remote from the clamps. These ears are grasped by the fingers. An operating lever attached directly to the cam projects outward from the end between the two ears and may be controlled with the thumb.

These and other aspects of the invention will be more apparent in the light of the following detailed description, taken in conjunction with the accompanying drawings in which:

Fig. 1 is a sectional elevation of a preferred form of the multiple clamp taken along the line I-l of Fig. 2;

Fig. 2 is an end elevation of the clamp of Fig. 1;

Fig. 3 isa fragmentary section taken along the 3 Fig. 5 is a fragmentary side view of the cam structure of Fig. 4.

Referring to the drawings, the clamp has a body It) cut from aluminum sheet or the like. For convenience in operation for anesthesia control, the clamp should be about 1 in major dimension and made of material about A" thick.

The clamp body is symmetrical and is provided with a pair of cars HlA, WB projecting opposite each other in the upper portion of the clamp. A somewhat similar pair of ears MA, MB project opposite each other in the lower portion of the clamp. Two clamping surfaces 12A, IEB are provided on the lower face of the clamp; Preferably these constitute a single plane.

On one side of the clamp body, adjacent the clamping face EZA, is a clamp 13 which is U- shaped and may be made conveniently from round rod. It has a short leg ISA Which projects through a bore 1 in the ear HA. leg 1313 which projects into another. bore it in the center portion of the clamp. The twolegs are parallel to each other and transverse to the central portion of the U. The bore it is large enough to accommodate a helical spring it through which the long leg passes. The lower end of the bore i5 is closed by a, bushing it through which the long leg passes. The upper end of the long leg is provided with a contact member I30. The lower portion of this member is cylindrical and. of such size that it slides easily in the bore l5. There is a plate-like projection 131) on the upper end of this contact member.

The apparatus is provided with a second clamp l8 disposed adjacent the clamping face i213. This clamp is substantially a mirror image of the clamp 53 and is U-shaped, with a short leg iEiA slidable in a bore 19 in the ear i 18, and a long leg IBB slidable in a central bore 29 within which is disposed a helical compression spring 2:. The

upper end of the long legxitB isprovided with a contact member MC with aplate-like projection 18D on its upper face. The long rod HEB slides in a bushing 22 which closes the lower end of the bore 28. V

The bores 65, 28 in which the long legs-or rods with their attached contact members are slidable terminate at their upper ends in a'journal 23. A cam 24 is mounted in this journal with its axis perpendicular to the plane defined by theaxes of the two long rods. The cam projects slightly outside the journal at thetop oi the clamp body and in this portion of the cam there is provided an operating lever '25 fastened rigidly to the cam.

The lower portion of the cam is provided with a peripheral slit 26. This slit is opposite the control lever, and the plate-like projections ISD, 181) on the contact members normally project into this slit. I

When the cam is rotated counterclockwise, as viewed in Fig. 1, the upper wall of the slit pushes the contact member I80 downwardly, opening the clamp 88. As soon as the control lever is released, the spring 21 immediately pushes this clamp closed. When the cam is rotated clockwise, it pushes open the right hand clamp it. However, the plate-like projection 53]) is in eiiect a catch, since its inside corner is cut away. Consequentiy, as the cam is rotated, the corner passesout of the slit 2S and the clamp is held open until pressure is exerted to force the cam in a'counteifclockwise direction. i

The assembly of the clamp structure just described is simple. The bushings are slid-over the respective long stems on the Us, the springs-are It has a long placed over these stems next and then the two contact members are screwed on the free ends of the long stems. The two clamps are then slid into their respective bores, and the bushings are press-fitted so that they are held tight in the lower ends of the two central bores. The clamps are then pulled out so that the short legs of each are outside their respective bores. The long stems of the clamps are rotatable in the bushings so that the short legs may be rotated slightly and held by the clamp faces with the clamps open. The cam is then pushed into its journal from the side, the short legs are replaced in the bores, and

the apparatus is ready to operate.

It will be observed that the two helical springs respective clamps and may be compressed sufficiently to permit these legs to be Withdrawn from their bores.

Considering the apparatus as viewed in Fig. l, the right hand clamp is the one designed to control the flow of saline solution, and may be locked open. The left hand clamp is the one for the control of the anesthetic proper, and it only remains open as long as the operating lever 25 is pressed counter-clockwise. Assuming that rubber tubes through which flow the two liquids have been placed in position in the two clamps and then connected with a glass Y or the like to a hypodermic needle, the flow of the two liquids is conveniently controlled by manipulation of the lever 25 on the cam. When the cam is pressed counterclockwise, the left hand clamp for the control of anesthetic is opened, but the other clamp remains closed. When the lever is pushed clockwise, the right hand clamp is opened, and if the lever is pushed suiliciently, the right hand clamp is locked open, and the left hand clamp remains closed. As long as the lever remains in the neutral position shown in Fig. 1, both clamps remain closed.

The operator grasps the clamps by the two upper ears lilA, iQB and manipulates the lever with his thumb.

If desired, the catch feature of the right hand clamp may be eliminated simply by forming the projection on its contact member in the way in which that of the left hand clamp is constructed.

The bushings ll, 22 shown in Fig. 1 are designed to be press-fitted into the ends of their respective bores. So assembled, the apparatus can not be taken apart readily, and consequently in some installations, the modification illustrated in Fig. 3 is desirable.

In Fig. 3 the parts common to Fig. l are indicated by the same reference numerals. The only difference is that a pin 39 passes through the clamp transverse to a plane defined by the two long rods of the clamps. This pin is cylindrical and its two edges project into notches SI, 32 in the sides of the two bushings. When the bushings are inserted with the notches in the proper position, the pin may be inserted through the clamp body, thus locking the two bushings in position and preventing the springs in the two bores from pushing the bushings out.

Fig. 4 illustrates a modified cam mechanisr which is the same in principle as that shown in Figs. 1 and 2 but may be preferable in apparatus exposed to salt, which tends to clog the cam. The cam of Fig. 1 comprises a solid disc 2d having a chordal slot 25 in which the members 48!) and MD operate. The disc 2% ma become cemented to its journal by salt. The cam of Figs. 4 and 5 is built'up of two outside discs 33, 34 andan in-,

side member 35. The three are held together by a coaxial pin 36 to which the operating lever 31 is attached. A chordal slot 38 similar to the slot 26 in the cam of Figs. 1 and 2 is provided.

The operation of the apparatus of Figs. 4 and 5 is the same as that of the apparatus ofFigs. 1 and 2 except that the cam may turn on the pin 36 while the two outside discs 33, 34 remain stationary. Therefore, the joint between the outside disc and the body of the clamp may become cemented with salt or the like without interfering with the operation of the apparatus.

The cam in Fig. 5 is shown in the position at which the clamp 13 is locked open due to the fact that the corner on the member BB is cut off as described hereinbefore with reference to Figs. 1 and 2.

Although we have described the invention with particular reference to the control of intravenous anesthetic, it will be appreciated that the device may be used for other intravenous injections or whenever two liquids are employed in parallel flow, the flow of one beinginterrupted when the other is begun.

We claim:

1. In a pinch clamp the combination which comprises a body having a clamping face and two bores extending inwardly therefrom in the body, two clamp arms disposed adjacent the clamping face, two rod members attached respectively to the clamp arms with their free ends slidably mounted in the bores, and a single cam rotatably mounted in the body and in contact with the free ends of the rod members and arranged to press either of the rods outward toward the clamping face without substantially moving the other rod.

2. In a pinch clamp the combination which comprises a body having a clamping face and two bores extending inwardly therefrom in the body, two clamp arms disposed adjacent the clamping face, two rod members attached respectively to the clamp arms with their free ends slidably mounted in the bores, spring means pressing the clamps toward the face, and a cam rotatably mounted in the body and in contact with the free ends of the rod members and arranged to press either of the rods outward the clamping face without substantially moving the other rod.

3. In a pinch clamp the combination which comprises a body having a clamping face and two bores extending inwardly therefrom in the body, two clamp arms disposed adjacent the clamping face, two rod members attached respectively to the clamps with their free ends slidably mounted in the bores, two springs mounted respectively in the bores and pressing the clamps toward the face, and a cam rotatably mounted in the body and in contact with the free ends of the rod members and arranged to press either of the rods outward toward the clamping face without substantially moving the other rod.

4. In a pinch clamp the combination which comprises a body having a clam ing face and four bores extending inwardly therefrom in the body, two clamp arms disposed adjacent the clamping face, two short rods attached to the respective clamp arms and slidable in two of the bores, two long rod members attached respectively to the clamp arms parallel to the short rods with their free ends slidably mounted in the other two bores, spring means pressing the clamp arms toward the face but permitting the short rods to be withdrawn from their respective bores, and a cam rotatably mounted in the body and in contact with the free ends of the long rod members and arranged to press either of the long rods outward toward the clamping face without substantially moving the other long rod.

5. Apparatus according to claim 4 in which the spring means comprise two helical springs mounted respectively in the bores of the long rod members.

6. Apparatus according to claim 4 provided with means for holding the cam in operative engagement with the free end of one of the rod members when said rod member is pressed out wardly by the cam.

7. Apparatus according to claim 4 in which the cam is circular but provided with a slot on one side into which the free ends of the long rod members project.

8. In a pinch clamp, the combination which comprises a body having clamping faces and two clamps adapted to press toward the respective faces, each clamp being provided with a long rod member attached rigidly thereto and slidably mounted in a bore passing into the body from the respective clamping face, and having a spring mounted in such bore for pressing the clamp toward its face, and a cam rotatably mounted in the body in contact with the free ends of the two rod members and adapted to push either outwardly in the direction of its clamp without pushing out the other.

9. Apparatus according to claim 8 in which the cam is mounted in the end of the body opposite the clamping faces, a lever projected from such end being mounted on the cam for rotating it.

10. Apparatus according to claim 8 in which the free end of one of the rod members is provided with a catch for holding it in fixed relationship with the cam when that rod is pushed out.

CHARLES MAYNARD WOODWARD. HARRY BERTHOLD BOLLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,427,455 Gates Aug. 29, 1922 2,129,055 Gibbs Sept. 6, 1938 

